How do I set sidebar with to have a color background

I have three questions:
1.) SIDEBAR COLOR BACKGROUND - I'm trying to create a color sidebar background on this site. You will see that I have set the color behind the Widgets already, but what I'm wondering is if there is a way to make it fill dynamically to the bottom of the page according to the various page heights of the main content areas.
2.) CHANGE WIDGET TITLE COLOR AND SIZE - I have tried to no avail using firebug to figure out how to change the color and size of the widget titles. Right now the color seems to be black (or #000000), or maybe the color of the main text which is too close to the background color.
3.) CONTENT AREA - Again, I have tried to find it in firebug, but I'm trying to change the margin around the whole content area to be 5 or 10 px instead of 15.
Any help will be greatly appreciated! Thanks.
Michele

1. Yes, that's what I mean! All the blog pages are obviously different heights depending on how much content is on it. I don't like how the blue column stopps where the widgets end.
2. I tried Batman's suggestion, but didn't work. I had already tried this which is why I need other trouble shooting.
3. Worked beautifully, thanks!

1. When I was working on a site, I couldn't figure out how to do just this until I found a CSS solution for it that requires you to set a specific sidebar height for each page. It's a pretty long way of doing it, but it works. The only the thing is, if the amount of content on a page changes, you will also need to adjust the height of the sidebar on that page. Do you want to try it out?

Catrina,
That's great! Actually, the second post Batman sent worked. I'm going to ignore point 1 for now, but if you want to send the code anyway that would be great... But don't do it if it's a lot of trouble. thanks!